To repeat a point I've made earlier on this thread, ARC HDMI problems appear to plague all electronics, even LeEco TVs, which were mentioned earlier. As much as the industry likes to aim for standardization, the reality is that when you set up a chain of electronic devices there are all sorts of subtle interactions between devices from different manufacturers that in my opinion are somewhat unpredictable.
You might simply be lucky to have some particular combination of TV, streaming device, audio device, etc. and encounter few problems. Unfortunately, most people seem to be unlucky in this regard, and I continue to believe the ARC is an imperfect technology. To abandon an excellent soundbar over these issues may launch one into a new episode of frustration with other devices. One great thing about Nakamichi is that when they promise a firmware upgrade it actually happens. This is not necessarily the case with many other manufacturers.
Just plug in the name of any electronic device along with "HDMI ARC problems" (or a similar search) and you'll see that these problems are pretty much ubiquitous.